Novel strain of Streptomyces sp. and a process for the preparation of an alkaline protease inhibitor

Abstract

The present invention provides a novel strain of Streptomyces sp. having Accession Number PTA 973 and a process for the preparation of an alkaline protease inhibitor employing the said strain.

1 . Streptomyces sp. strain having accession number PTA 973 and deposited at American Type Culture Collection, USA.  
     
     
         2 . A process for the preparation of a proteinaceous alkaline protease inhibitor, which comprises the steps of: 
 (i) growing Streptomyces sp. in a fermentation medium containing assimilable carbon and nitrogen sources at a temperature in the range of 28-30° C. for a period of atleast 96 hrs.,    (ii) separating the solids by conventional method to obtain cell free liquid, and    (iv) recovering the protease inhibitor by conventional precipitation method from the cell free liquid using known salting out agent.    
     
     
         3 . A process as claimed in  claim 2  wherein the fermentation medium comprises assimilable carbon and nitrogen sources and micro-ingredients.  
     
     
         4 . A process as claimed in  claim 2  wherein the assimilable carbon source is selected from starch, glycerol glucose, sucrose, mannose, lactose and sorbitol.  
     
     
         5 . A process as claimed in  claim 2  wherein the nitrogen source is selected from casein, asparagine, potassium nitrate, skimmed milk, soyabean meal, yeast extract, malt extract, peptone, casamino acids and urea.  
     
     
         6 . A process as claimed in  claim 2  wherein the fermentation medium further comprises: 
 1. Starch—0.5-1%  
 2. Casein—0.05-0.1%  
 3. Potassium nitrate—0.1-0.2%  
 4. Sodium chloride—0.1-0.2%  
 5. Dipotassium hydrogen phosphate—0.1-0.2%  
 6. Magnesium sulfate—0.002-00005%  
 7. Calcium carbonate—0.001-0.002%  
 8. Ferrous sulfate—0.001%  
 
     
     
         7 . A process as claimed in  claim 2  wherein the fermentation medium is supplemented with sulfate, phosphate or carbonate salts of metals selected from Na, K, Ca, Mg and Fe.  
     
     
         8 . A process as claimed in  claim 2  wherein the salting out agent is ammonium sulfate.  
     
     
         9 . A process as claimed in  claim 2  wherein the protease inhibitior is recovered by centrifugation.  
     
     
         10 . A process as claimed in  claim 2  wherein the alkaline protease inhibitor exhibits antifungal activities against fungal pathogens selected from Trichoderma, Fusarium, Alternaria and Rhizoctonia.  
     
     
         11 . A bio-control agent comprising the alkaline protease inhibitor prepared according to the process claimed in  claim 2 .  
     
     
         12 . A biodegradable antifungal agent comprising the alkaline protease inhibitor prepared according to the process claimed in  claim 2.